Foreign visitors may have noticed the isolated wall either outside or just inside the gate of a traditional Chinese house to shield the rooms from outsiders' view. Known as a "screen wall" in English, it is called yingbi or zhaobi in Chinese. It can be made of any material-brick, wood, stone or glazed tile.

The yingbi dates back at least to the Western Zhou Dynasty (11 century B. C. to 771 B.C.). Archaeologists have discovered in recent years from tombs of that period in Shaanxi Province what remains of a screen wall. It measures 240 cm long and 20 cm high. This is the earliest known wall of its kind in China at the time of writing.

In ancient times, the yingbi was a symbol of rank. According to the Western Zhou system of rites, only royal palaces, noblemen's mansions and religious temples could have a screen wall. Apart from keeping passers-by from peeping into the courtyard, the screen wall could also be used by the visitor, who would get off from his carriage and, standing behind the wall, tidy up his dress before going in. It was not until much later that private houses (mainly the quadrangles of bungalows in the northern parts of the country) began to have screen walls.

The most exquisite of all ancient screen walls are three "nine-dragon walls" built of glazed colour tiles. The largest of these, 45.5m X 8m X 2.02m, is now in the city of Datong, Shanxi Province. It originally stood in front of the princely mansion of the thirteenth son of Zhu Yuanzhang, first emperor of the Ming Dynasty. Sculpted on it in seven different colours are nine dragons flying in clouds. The most splendid of the three is the one which belonged to a palace of the Ming Dynasty and now stands north of the lake in Beijing's Beihai Park. It is a mosaic of glazed colour tiles showing on each side nine curly dragons in relief. An observant visitor could also count 635 dragons of smaller sizes on the ridges and roof tiles of the wall. The third of these walls stands opposite the gate Huangjimen in the Forbidden City and is well-known to sightseers. All the three mentioned above were built during the Ming Dynasty (1368-1644) and all used to stand in front of the entrance to a courtyard, making a component part of the architectural complex and adding to the magnificence of the buildings.

Besides these, there are also screen walls with one, three or five dragons to be seen in different parts of the country.

There is a screen wall in each of the side palace courtyards of the Forbidden City. Whether made of wood, carved out of marble or built with glazed tiles, it is invariably a fine piece of work with designs symbolic of good luck.

Certain screen walls found in the eastern provinces of China bear the image of a strange animal called tan, either carved in brick or painted in colour. According to local belief, this animal was so greedy that it wanted to devour the rising sun on the sea, meeting its own death by drowning. The picture serves as a reminder that greed leads to self-destruction.

In the vicinity of the Five Dragon Pavilions (Wulongting) in the Beihai Park of Beijing, there is a so-called "iron screen wall," a relic from the Yuan Dynasty of the thirteenth century. At first glance, it appears to have been cast of iron but actually it is a piece of volcanic rock. Carved on it in vivid style are, on one side, lions playing with a ball and, on the other, a legendary unicorn; it is noted for its antiquity and simplicity of execution.